The flag --envoy-admin-access-enable-ipv6=true has no effect on envoy sidecar containers

[jgaynon]

Describe the bug
Setting the flag --envoy-admin-access-enable-ipv6=true in the controller deployment config should set the ENVOY_ADMIN_ACCESS_ENABLE_IPV6 env var to true for all envoy sidecar containers. It does not, and the env var is always set to false.

Steps to reproduce
Set the flag --envoy-admin-access-enable-ipv6=true in the appmesh controller deployment config. Create a pod with an envoy sidecar container. ENVOY_ADMIN_ACCESS_ENABLE_IPV6 will still be set to false in the sidecar's pod config.

Expected outcome
ENVOY_ADMIN_ACCESS_ENABLE_IPV6 should be set to true in the sidecar's pod config, and the admin endpoint should accept IPv6 connections.

Environment

• App Mesh controller version: v1.13.1
• Envoy version: v1.29.6.0-prod
• Are you using any integrations? X-ray, Jaeger etc. If so versions?: No.
• Kubernetes version: v1.28
• Using EKS (yes/no), if so version?: Yes, v1.28

Additional Context:
This currently makes it impossible for me to use the appmesh controller with Bottlerocket nodes as localhost resolves to IPv6, so the envoy pod readiness probe fails to connect.